1. 1
   A student examines a copy of the periodic table, noticing that the elements are listed in a particular numerical order, and that elements with similar properties appear in the same vertical columns.

   (a)

   A student examines a copy of the periodic table and notices that the elements are listed in a particular order, starting with hydrogen. What is the periodic table arranged in order of?

   [1 mark]

   • AAtomic (proton) number
   • BRelative atomic mass, always increasing exactly
   • CNumber of neutrons
   • DAlphabetical order of element names

   (b)

   What term is given to the vertical columns of the periodic table, in which elements with similar properties are found?

   [1 mark]

   • AGroups
   • BPeriods
   • CSeries
   • DBlocks

   (c)

   Explain what is meant by 'periodicity' in the context of the periodic table, giving an example.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Lithium, sodium and potassium are all found in Group 1 of the periodic table, and all three react vigorously and in a similar way when added to water.

   (a)

   What do elements in the same group have in common that explains this?

   [1 mark]

   • AThe same number of electrons in their highest occupied energy level
   • BExactly the same relative atomic mass
   • CExactly the same number of neutrons
   • DExactly the same number of electron shells

   (b)

   Why do lithium, sodium and potassium have similar chemical properties, even though they have different numbers of electron shells?

   [1 mark]

   • AThey have the same number of electrons in their outer shell, which mainly determines chemical properties
   • BThey all have exactly the same total number of electrons
   • CThey all have the same mass number
   • DThey are all found in the same period of the periodic table

   (c)

   Explain why lithium, sodium and potassium react in a similar way with water.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   The scientist Mendeleev produced an early version of the periodic table, arranging the known elements of his time and leaving several gaps where he believed undiscovered elements should exist.

   (a)

   Describe how Mendeleev's work relates to the modern periodic table used today.

   [3 marks]

   (b)

   Explain why Mendeleev leaving gaps in his periodic table, rather than simply listing all known elements in a continuous row, was important evidence in support of his arrangement.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Helium, neon and argon are all members of Group 0 of the periodic table, known as the noble gases, and are all observed to be extremely unreactive under normal conditions.

   (a)

   Explain why these noble gases are so unreactive, referring to their electron arrangements.

   [6 marks]

   (b)

   Explain how the periodic table is organised, referring to atomic number, groups and periodicity, and explain how the stable electron arrangement of the noble gases helps to explain the properties of elements in other groups, such as Group 1 and Group 7.

   [6 marks]

   Total for question 4: 12 marks

End of questions